Removing a bandage adhered to the skin can be very painful. In addition, people with fragile or delicate skin or with chronic wounds that require repeated applications of dressings are often concerned about skin stripping and other damage.
The conflicting requirements of high adhesion to skin so that a bandage stays secure and gentle removal so that skin is not stripped, hair is not pulled, and residue is not left behind has been approached in various ways. These approaches include, for example, increasing the breathability of the adhesive to maintain good skin integrity for lower removal trauma (see, for example, U.S. Pat. No. 5,614,310), “stretch release” technology (see, for example, U.S. Pat. No. 7,078,582), reinforcing the skin with a film forming polymer prior to applying the bandage (see, for example, U.S. Pat. No. 4,324,595), and migrating a debonding agent like body lotion or hexamethyl disiloxane through a porous backing to the skin/adhesive interface (see, for example, U.S. Pat. No. 6,136,866). Many of these approaches compromise in-use adhesion, however, and others require an extra step.
Because of theses drawbacks, there has been interest in using water-soluble pressure sensitive adhesives (PSAs) to make hurt-free bandages that readily dissolve off in water. Unfortunately, most water-soluble PSAs pick up moisture, which reduces their cohesive strength. Water-soluble patches comprising a water-soluble adhesive and water-soluble backing for delivery of an active ingredient are described in U.S. Patent Application Pub. No. 2002/0187181. These patches, for example, need to be manufactured under low humidity conditions and packaged individually in foil packaging to prevent excess uptake of moisture in humid environments.